This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | -1 |
| 2 | 4 |
| 3 | 0 |
| 4 | -1654 |
| 5 | 102750 |
| 6 | -4079389 |
| 7 | -178722208 |
| 8 | 83191059372 |
| 9 | -14561829897345 |
| 10 | 1115121827539325 |
| 11 | 403631463559529040 |
| 12 | -251989999508801085674 |
| 13 | 76158421344845152140737 |
| 14 | -3994730250899559184766830 |
| 15 | -13162858116922635098226480000 |
| 16 | 10823217968258750568539067678392 |